Method for placing a medical agent into a vessel of the body

ABSTRACT

A method for placing an embolic coil into an aneurysm utilizing a delivery system having a deflected distal section. The delivery system stabilizes an embolic coil deployment system thereby placing the embolic coil with greater accuracy.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention concerns a novel method for placing a medicalagent into a vessel of a patient, in particular, placing embolic coilsinto an aneurysm of the brain.

[0003] 2. Description of the Prior Art

[0004] For many years physicians have been placing various deviceswithin a blood vessel of the human body in order to treat aneurysms orto occlude a vessel at a particular location. Such devices are placedwithin the aneurysm or vessel using a deployment system. When a deviceis deployed into the vessel but misses its intended position, it isdifficult, if not impossible to retrieve or reposition the device. Tohelp alleviate this problem, a delivery system is employed to increasethe probability of placing the device precisely at a pre-selectedposition. A variety of delivery systems exist to provide stability andincrease deployment accuracy. The combination of different devices,deployment systems, and delivery systems provide physicians withreliable methods of treating aneurysms.

[0005] Various types of devices are placed within an aneurysm or avessel to occlude the flow of blood through the vessel by promotingthrombus formation at a particular location. Such devices includedilation balloons, radiopaque fluids, liquid medications, and emboliccoils. Embolic coils may take the form of helically wound coils,randomly wound coils, coils wound within other coils, or many other coilconfigurations. These coils are generally formed of radiopaque metallicmaterials, such as platinum, gold, and tungsten, or alloys of thesemetals. Often times, several coils are placed at a given location inorder to occlude the flow of blood through the vessel.

[0006] One example of an embolic coil design is disclosed in U.S. Pat.No. 6,179,857 entitled, “Stretch Resistant Embolic Coil With VariableStiffness.” The coil is a helically wound coil in which variouscombinations of adjacent turns are spot welded together to create astretch resistant coil of a pre-selected flexibility. Another coilconfiguration is disclosed in U.S. Pat. No. 6,183,491 entitled, “EmbolicCoil Deployment System With Improved Embolic Coil,” which shows anembolic coil having a relatively flexible proximal portion which resistsstretching.

[0007] Also, U.S. Pat. No. 5,853,418 entitled, “Stretch ResistantVaso-occlusive Coils,” discloses a helically wound coil having apolymeric stretch resisting member extending through the lumen of thecoil and fixedly attached to both the distal end and the proximal end ofthe coil. Other examples of coil configurations are disclosed in U.S.Pat. No. 5,334,210 entitled, “Vascular Occlusion Assembly” and U.S. Pat.No. 5,382,259 entitled, “Vasoocclusion Coil With Attached Tubular WovenOr Braided Fibrous Covering.” With all coil designs, it is importantthat embolic coils remain very flexible for traveling through vesselswhen used with deployment systems.

[0008] A variety of deployment systems are available for placing emboliccoils within an aneurysm or vessel. An example of such a system isdisclosed in U.S. Pat. No. 6,113,622 entitled, “Embolic Coil HydraulicDeployment System,” assigned to the same assignee as the present patentapplication. The disclosure of the above patent is incorporated into andmade part of this patent application. The hydraulic embolic coildeployment system uses fluid pressure which is applied to the distalsection of the deployment catheter for expanding the distal sectionradially to release the embolic coil at a pre-selected position.

[0009] Another coil deployment system utilizes a deployment catheterhaving a socket at the distal end for retaining a ball which is bondedto the proximal end of the coil. The ball is placed in the socket withina lumen at the distal end of the deployment catheter, and the deploymentsystem is then moved into a vessel to place the coil at a desiredposition. Then, a pusher wire with a piston at the end is pusheddistally from the proximal end of the deployment catheter to therebypush the ball out of the socket and release the coil at the desiredposition. This system is disclosed in U.S. Pat. No. 5,350,397 entitled,“Axially Detachable Embolic Coil Assembly.”

[0010] Also, U.S. Pat. No. 5,263,964 entitled, “Coaxial TractionDetachment Apparatus And Method,” discloses another coil deploymentsystem. This system uses glue or solder for attaching the embolic coilto a guidewire which is, in turn, placed within a flexible deploymentcatheter for positioning the coil within the vessel at a pre-selectedposition. Once the coil is at the desired position, the coil isrestrained by the deployment catheter, and the guidewire is pulled fromthe proximal end of the deployment catheter causing the coil to bedetached from the guidewire and released from the deployment system.

[0011] Examples of other deployment systems are disclosed in U.S. Pat.No. 5,122,136 entitled, “Endovascular Electrolytically DetachableGuidewire Tip For The Electroformation Of Thrombus In Arteries, Veins,Aneurysms, Vascular Malformations And Arteriovenous Fistulas” and U.S.Pat. No. 5,108,407 entitled, “Method And Apparatus For Placement Of AnEmbolic Coil.” Even though fluoroscopic visualization shows physiciansgeneral movement of an embolic coil through the vasculature of the bodyand the use of coil deployment systems allow physicians to control whenthe embolic coil is released, it is still difficult to precisely place acoil at a pre-selected location, such as a location within an aneurysm.However, with the use of a delivery system, it is possible to stabilizethe deployment system within a vessel in order to more precisely placean embolic coil.

[0012] An example of such a delivery system is disclosed in U.S. patentapplication Ser. No. 09/894,735, entitled “Method And Apparatus ForPlacing A Medical Agent Into A Vessel Of The Body,” filed on Jun. 28,2001 and in U.S. patent application Ser. No. 09/894,421, entitled,“Method And Apparatus For Placing A Medical Agent Into A Vessel Of TheBody,” filed on Jun. 28, 2001, both assigned to the same assignee as thepresent patent application. These patent applications are incorporatedby reference and are made a part of the present patent application. Thedelivery catheter disclosed in this patent application has two lumens.The first lumen has a shape retaining wire which extends therethroughfor shaping an intermediate section of the delivery catheter into agenerally U-shaped configuration. The second lumen has a side opening ata location within the intermediate section of the delivery catheter. Theside opening is positioned over an aneurysm, and then the embolic coildeployment system is inserted through the second lumen and into aposition proximal the aneurysm. The U-shaped delivery catheterstabilizes the deployment system as the embolic coil is released intothe aneurysm.

[0013] Another delivery system used to stabilize a coil deploymentsystem is disclosed in U.S. patent application Ser. No. 09/878,530entitled, “Delivery System Using Balloon Catheter,” filed on Jun. 11,2001 and assigned to the same assignee as the present patentapplication. The delivery catheter disclosed in this patent applicationincludes a balloon adjacent to the distal end and an inflation port atthe proximal end of the catheter for inflating the balloon. The deliverycatheter is positioned within the vessel of a patient, and the balloonis inflated to stabilize the position of the delivery catheter. Then, anembolic coil deployment system is introduced into the delivery catheterand through a side opening of the catheter to deliver the embolic coilinto the aneurysm.

[0014] When physicians use a delivery system in combination with a coildeployment system, the delivery system stabilizes the coil deploymentsystem, and the coil may be placed with greater accuracy. Therefore, itis an objective of this invention to provide a method for placingembolic coils with increased accuracy. Furthermore, it is an objectiveto provide a system which is relatively simple in construction and easyto use.

SUMMARY OF THE INVENTION

[0015] In accordance with one aspect of the present invention, a methodis provided for placing an embolic agent into an aneurysm. The methodincludes the use of a delivery catheter having a proximal section, anintermediate section, and a distal section which is formed from aflexible polymeric material. The delivery catheter includes a firstlumen, a second lumen, and a pre-shaped retaining wire which extendsthrough the first lumen to form a normally deflected distal section. Themethod includes the steps of inserting a straightening wire into thesecond lumen of the delivery catheter to cause the normally deflecteddistal section of the delivery catheter to become relatively straight,introducing the delivery catheter into a vessel of a patient to aposition where the normally deflected distal section is generallyaligned with the aneurysm, withdrawing the straightening wire from thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to again become deflected and thereby move to a positionproximate to the aneurysm, introducing an embolic agent deploymentsystem into the second lumen of the delivery catheter and through thenormally deflected distal section. The method also includes the steps ofdelivering the embolic agent into the aneurysm with the embolic coildeployment system, withdrawing the embolic agent deployment system fromthe delivery catheter, again inserting the straightening wire into thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to become relatively straight, and thereafter withdrawingthe delivery catheter from the vessel of the patient.

[0016] In accordance with a similar aspect of the present invention, theembolic agent deployment system takes the form of an embolic coildeployment system, and the embolic agent takes the form of an emboliccoil.

[0017] In accordance with another aspect of the present invention, amethod is provided for placing an embolic agent into an aneurysm. Thismethod includes the use of a delivery catheter having a proximalsection, an intermediate section, and a distal section which is formedfrom a flexible polymeric material. The delivery catheter includes afirst lumen, a second lumen, and a shape retaining wire which extendsthrough the first lumen. The method also includes the use of an embolicagent deployment system having an elongated, flexible deploymentcatheter with a lumen extending therethrough. The deployment catheterincludes a distal section being formed of a material with a durometerwhich exhibits the characteristic that when a fluid pressure is appliedto the lumen the walls of the distal section of the deployment catheterexpand radially. The deployment catheter also includes a source ofpressure coupled to the proximal section for applying a fluid pressureto the lumen and an embolic agent being disposed in fluid-tightengagement with the lumen of the distal section. The method includes thesteps of shaping the distal section of the delivery catheter to form anormally deflected distal section, inserting a straightening wire intothe second lumen of the delivery catheter to cause the normallydeflected distal section of the delivery catheter to become relativelystraight, introducing the delivery catheter into a vessel of a patientto a position where the normally deflected distal section is generallyaligned with the aneurysm, withdrawing the straightening wire from thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to again become deflected and thereby move to a positionproximate to the aneurysm, introducing an embolic agent deploymentsystem into the second lumen of the delivery catheter and through thenormally deflected distal section. The method also includes the step ofapplying fluid pressure to the lumen of the embolic agent deploymentsystem thereby causing the walls of the distal section of the embolicagent deployment system to expand and release the embolic agent.Finally, the method includes withdrawing the embolic agent deploymentsystem from the delivery catheter, again inserting the straighteningwire into the second lumen of the delivery catheter to cause thenormally deflected distal section to become relatively straight, andthereafter withdrawing the delivery catheter from the vessel of thepatient.

[0018] In accordance with a similar aspect of the present invention, theembolic agent deployment system takes the form of an embolic coildeployment system, and the embolic agent takes the form of an emboliccoil

[0019] In accordance with still another aspect of the present invention,a method is provided for placing an embolic agent into an aneurysm. Themethod includes the use of a delivery catheter having a proximalsection, an intermediate section, and a distal section which is formedfrom a flexible polymeric material. The delivery catheter includes alumen and a normally deflected distal section which is pre-shaped. Themethod includes the steps of inserting a straightening wire into thelumen of the delivery catheter to cause the normally deflected distalsection of the delivery catheter to become relatively straight,introducing the delivery catheter into a vessel of a patient to aposition where the normally deflected distal section is generallyaligned with the aneurysm, withdrawing the straightening wire from thelumen to cause the normally deflected distal section to again becomedeflected and thereby move to a position proximate to the aneurysm,introducing an embolic agent deployment system into the lumen of thedelivery catheter and through the normally deflected distal section. Themethod also includes the steps of delivering the embolic agent into theaneurysm with the embolic agent deployment system, withdrawing theembolic agent deployment system from the delivery catheter, againinserting the straightening wire into the lumen of the delivery catheterto cause the normally deflected distal section to become relativelystraight, and thereafter withdrawing the delivery catheter from thevessel of the patient.

[0020] In accordance with a similar aspect of the present invention, theembolic agent deployment system takes the form of an embolic coildeployment system, and the embolic agent takes the form of an emboliccoil.

[0021] In accordance with another aspect of the present invention, amethod is provided for placing an embolic coil into an aneurysm orvessel. The method includes the use of a delivery catheter having aproximal section, an intermediate section, and a distal section which isformed from a flexible polymeric material. The delivery catheterincludes a lumen and a distal section which is shape retaining. Themethod includes the steps of shaping the distal section of the deliverycatheter to form a normally deflected distal section, inserting astraightening wire into the lumen of the delivery catheter to cause thenormally deflected distal section of the delivery catheter to becomerelatively straight, introducing the delivery catheter into a vessel ofa patient to a position where the normally deflected distal section isgenerally aligned with the aneurysm, withdrawing the straightening wirefrom the lumen of the delivery catheter to cause the normally deflecteddistal section to again become deflected and thereby move to a positionproximate to the aneurysm, introducing an embolic agent deploymentsystem into the lumen of the delivery catheter and through the normallydeflected distal section. The method also includes the steps ofdelivering the embolic agent into the aneurysm with the embolic agentdeployment system, withdrawing the embolic agent deployment system fromthe delivery catheter, again inserting the straightening wire into thelumen of the delivery catheter to cause the normally deflected distalsection to become relatively straight, and thereafter withdrawing thedelivery catheter from the vessel of the patient.

[0022] In accordance with a similar aspect of the present invention, theembolic agent deployment system takes the form of an embolic coildeployment system, and the embolic agent takes the form of an emboliccoil.

[0023] In accordance with still another aspect of the present invention,a method is provided for placing an embolic agent into an aneurysm. Thismethod includes the use of a delivery catheter having a proximalsection, an intermediate section, and a distal section which is formedfrom a relatively flexible polymeric material. The delivery catheterincludes a first lumen and a second lumen. The method includes the stepsof inserting a straightening wire into the second lumen of the deliverycatheter, inserting a pre-shaped retaining wire into the first lumen ofthe delivery catheter to form a normally deflected distal section,introducing the delivery catheter into a vessel of a patient to aposition where the normally deflected distal section is generallyaligned with the aneurysm, withdrawing the straightening wire from thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to again become deflected and thereby move to a positionproximate to the aneurysm, introducing an embolic agent deploymentsystem into the second lumen of the delivery catheter and through thenormally deflected distal section. The method also includes deliveringthe embolic agent into the aneurysm with the embolic agent deploymentsystem, withdrawing the embolic agent deployment system from thedelivery catheter, again inserting the straightening wire into thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to become relatively straight, and thereafter withdrawingthe delivery catheter from the vessel of the patient.

[0024] In accordance with a similar aspect of the present invention, theembolic agent deployment system takes the form of an embolic coildeployment system, and the embolic agent takes the form of an emboliccoil.

[0025] In accordance with another aspect of the present invention, amethod is provided for placing an embolic agent into an aneurysm. Thismethod includes the use of a delivery catheter having a proximalsection, an intermediate section, and a distal section which is formedfrom a relatively flexible polymeric material. The delivery catheterincludes a first lumen and a second lumen. The method includes the stepsof inserting a shape retaining wire into the first lumen of the deliverycatheter, shaping the distal section of the delivery catheter to form anormally deflected distal section, inserting a straightening wire intothe second lumen of the delivery catheter to cause the normallydeflected distal section of the delivery catheter to become relativelystraight, introducing the delivery catheter into a vessel of a patientto a position where the normally deflected distal section is generallyaligned with the aneurysm, withdrawing the straightening wire from thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to again become deflected and thereby move to a positionproximate to the aneurysm, introducing an embolic agent deploymentsystem into the second lumen of the delivery catheter and through thenormally deflected distal section. The method also includes deliveringthe embolic agent into the aneurysm with the embolic agent deploymentsystem, withdrawing the embolic agent deployment system from thedelivery catheter, again inserting the straightening wire into thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to become relatively straight, and thereafter withdrawingthe delivery catheter from the vessel of the patient.

[0026] In accordance with a similar aspect of the present invention, theembolic agent deployment system takes the form of an embolic coildeployment system, and the embolic agent takes the form of an emboliccoil.

[0027] In accordance with still another aspect of the present invention,a method is provided for placing a medical agent into a vessel. Themethod includes the use of a delivery catheter having a proximalsection, an intermediate section, and a distal section which is formedfrom a flexible polymeric material. The delivery catheter includes afirst lumen, a second lumen, and a pre-shaped retaining wire whichextends through the first lumen to form a normally deflected distalsection. The method includes the steps of inserting a straightening wireinto the second lumen of the delivery catheter to cause the normallydeflected distal section of the delivery catheter to become relativelystraight, introducing the delivery catheter into the vessel of a patientto a position where the normally deflected distal section is generallyaligned with a pre-selected position within the vessel, withdrawing thestraightening wire from the second lumen of the delivery catheter tocause the normally deflected distal section to again become deflectedand thereby move to the pre-selected position within the vessel,introducing a medical agent deployment system into the second lumen ofthe delivery catheter and through the normally deflected distal section.The method also includes the steps of delivering the medical agent intothe vessel with the medical agent deployment system, withdrawing themedical agent deployment system from the delivery catheter, againinserting the straightening wire into the second lumen of the deliverycatheter to cause the normally deflected distal section to becomerelatively straight, and thereafter withdrawing the delivery catheterfrom the vessel of the patient.

[0028] In accordance with another aspect of the present invention, amethod is provided for placing a medical agent into a vessel. The methodincludes the use of a delivery catheter having a proximal section, anintermediate section, and a distal section which is formed from aflexible polymeric material. The delivery catheter includes a lumen anda normally deflected distal section which is pre-shaped. The methodincludes the steps of inserting a straightening wire into the lumen ofthe delivery catheter to cause the normally deflected distal section ofthe delivery catheter to become relatively straight, introducing thedelivery catheter into the vessel of a patient to a position where thenormally deflected distal section is generally aligned with apre-selected position within the vessel, withdrawing the straighteningwire from the lumen to cause the normally deflected distal section toagain become deflected and thereby move to the pre-selected positionwithin the vessel, introducing a medical agent deployment system intothe lumen of the delivery catheter and through the normally deflecteddistal section. The method also includes the steps of delivering themedical agent into the vessel with the medical agent deployment system,withdrawing the medical agent deployment system from the deliverycatheter, again inserting the straightening wire into the lumen of thedelivery catheter to cause the normally deflected distal section tobecome relatively straight, and thereafter withdrawing the deliverycatheter from the vessel of the patient.

[0029] In accordance with still another aspect of the present invention,a method is provided for placing a medical agent into a vessel. Thismethod includes the use of a delivery catheter having a proximalsection, an intermediate section, and a distal section which is formedfrom a relatively flexible polymeric material. The delivery catheterincludes a first lumen and a second lumen. The method includes the stepsof inserting a straightening wire into the second lumen of the deliverycatheter, inserting a pre-shaped retaining wire into the first lumen ofthe delivery catheter to form a normally deflected distal section,introducing the delivery catheter into a vessel of a patient to aposition where the normally deflected distal section is generallyaligned with a pre-selected position within the vessel, withdrawing thestraightening wire from the second lumen of the delivery catheter tocause the normally deflected distal section to again become deflectedand thereby move to the pre-selected position within the vessel,introducing a medical agent deployment system into the second lumen ofthe delivery catheter and through the normally deflected distal section.The method also includes delivering the medical agent into the vesselwith the medical agent deployment system, withdrawing the medical agentdeployment system from the delivery catheter, again inserting thestraightening wire into the second lumen of the delivery catheter tocause the normally deflected distal section to become relativelystraight, and thereafter withdrawing the delivery catheter from thevessel of the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030]FIG. 1 is an enlarged, partially sectioned view of a deliverycatheter having a normally deflected distal section;

[0031]FIG. 2 is a partially sectioned view showing an embolic coildeployment system used with the delivery catheter of FIG. 1 to deploy anembolic coil;

[0032]FIG. 3 is an enlarged, partially sectioned view of the deliverycatheter in use to deploy an embolic coil into an aneurysm;

[0033]FIG. 4 is a cross-sectional view of the delivery catheter, takenalong the plane of the line 4-4′ of FIG. 3; and,

[0034] FIGS. 5-8 are diagrammatic sequential views of a method ofplacing embolic coils within an aneurysm.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0035]FIG. 1 illustrates a preferred embodiment of the delivery catheterof the present invention which generally includes a delivery catheter 10connected to the distal end of a connector 26. More particularly, thedelivery catheter 10 includes a first lumen 18 and a second lumen 20.The first lumen 18 extends from the proximal end to the distal end ofthe delivery catheter 10 and includes a pre-shaped retaining wire 22.The pre-shaped retaining wire 22 is bent proximal of the distal section16 thereby causing the distal section 16 to be deflected angularly awayfrom the center line of the delivery catheter 10. The second lumen 20extends the entire length of the delivery catheter 10 and communicateswith a lumen 28 which extends from the proximal end to the distal end ofthe connector 26.

[0036] While the delivery catheter 10 may be constructed of variousflexible materials including various polymers, the delivery catheter 10is preferably formed in three different sections with materials havingdifferent durometers and different polymer compositions. The proximalsection 12 of the delivery catheter 10 is preferably formed of a nylonmaterial having a durometer of approximately 75 D and extends for alength of about 100 centimeters. The intermediate section 14 ispreferably formed of a nylon material having a durometer ofapproximately 65 D and extends for a length of about 40 centimeters. Thedistal section 16 is preferably formed of a polyurethane material havinga durometer of approximately 80 AE and is about 5 centimeters in length.With this construction the delivery catheter 10 is sufficiently flexibleto be introduced through the various tortuous vessels of the human brainbut at the same time provides sufficient rigidity for inserting thedelivery catheter into and through these vessels. This construction alsomakes possible the ease of deflection of the distal section 16.

[0037]FIG. 2 illustrates a hydraulic embolic coil deployment system 100which is comprised of a hydraulic injector, or syringe 102, coupled tothe proximal end of a deployment catheter 104. An embolic coil 106 isdisposed within the lumen at the distal section 108 of the deploymentcatheter. The proximal end of the coil 106 is tightly held within thelumen of the distal section 108 until the deployment device is activatedfor release of the coil. As shown, the syringe 102 includes a threadedpiston 110 which is controlled by the handle 112 for infusing fluid intothe interior of the deployment catheter 104. Also, as illustrated, thedeployment catheter 104 includes a winged hub 114 which aids in theinsertion of the deployment catheter 104.

[0038] Preferably, the distal section 108 of the deployment catheter 104is formed of a polymeric material with a relatively low durometer whichexhibits the characteristic that, when a fluid pressure of approximately90 to 450 psi is applied to the interior of the deployment catheter, thewalls of the distal section 108 expand radially, to thereby release theproximal end of the embolic coil 106. A more detailed description of thehydraulic embolic coil deployment system is disclosed in U.S. Pat. No.6,113,622, assigned to the same assignee as the present patentapplication.

[0039]FIG. 3 illustrates, in detail, the delivery catheter 10 which hasbeen inserted into a blood vessel 30 of the brain. The pre-shapedretaining wire 22 extends through the first lumen 18, and the distalsection 16 is deflected to generally align with the aneurysm 32. Theembolic coil deployment system 100 is shown inserted through the secondlumen 20 of the delivery catheter 10 in order to place an embolic coil106 into an aneurysm 32.

[0040]FIG. 4 illustrates a cross-sectional view taken through thedelivery catheter 10 at a location indicated by 4-4′ shown in FIG. 3.More particularly, FIG. 4 illustrates the location where the pre-shapedretaining wire 22 extends through the first lumen 18. Also illustratedis an end view of the embolic coil deployment system 100 which passesthrough the second lumen 20 of the delivery catheter 10.

[0041]FIGS. 5 through 8 are provided for an understanding of theoperation of the delivery catheter 10 used in conjunction with theembolic coil deployment system 100. As illustrated in FIG. 5, thedelivery catheter 10 is inserted into a vessel 30 over a straighteningwire 24 in the second lumen 20. The delivery catheter 10 is thenpositioned such that the distal section 16 is generally aligned with theaneurysm 32. Next, the straightening wire 24 is removed, and asillustrated in FIG. 6, the distal section 16 of the delivery catheter 10normally deflects thereby causing the distal section 16 to move to aposition proximate to the aneurysm 34. Once the distal section 16 hasbeen positioned, the embolic coil deployment system 100 may then beinserted into the second lumen 20 and through the distal section 16 asillustrated in FIG. 7. Then, the embolic coil 106 may be placed into theaneurysm 32 and released from the deployment system 100 as illustratedin FIG. 8. The deployment system 100 may then be removed, and thisprocess may be repeated until a sufficient number of embolic coils 106have been placed into the aneurysm 32. When the aneurysm 32 has beensufficiently filled with embolic coils, the coil deployment system 100may be removed from the delivery catheter 10. Thereafter, thestraightening wire 24 may be again inserted into the second lumen 20thereby causing the distal section 16 of the delivery catheter 10 tostraighten within the vessel. Then, the delivery catheter 10 may beeasily withdrawn from the vessel 30 and from the body of the patient.

[0042] A novel system has been disclosed in which an embolic coil isdelivered precisely to a pre-selected position. Although a preferredembodiment of the invention has been described, it is to be understoodthat various modifications may be made by those skilled in the artwithout departing from the scope of the present invention. For example,instead of delivering an embolic coil to an aneurysm, a medical agentmay be placed within a vessel.

[0043] Also, the delivery catheter may be constructed with a shaperetaining wire disposed in the first lumen. In this case a physician mayshape the distal section into a deflected configuration prior to use.

[0044] In another alternative construction, the delivery catheter may becomprised of a single lumen having neither a pre-shaped retaining wirenor a shape retaining wire. Instead, the delivery catheter is formed ofa shape retaining polymer which may be heat set to deflect the distalsection, either by the manufacturer or by the physician prior to use.

[0045] Furthermore, a pre-shaped retaining wire or a shape retainingwire could be inserted into a dual lumen catheter. By introducing eitherwire into a lumen of the delivery catheter, the manufacturer orphysician could deflect the distal section.

[0046] In a final alternative construction, the sections of the deliverycatheter could be sections of a unitary structure with changingdurometers.

[0047] These and other modifications would be apparent to those havingordinary skill in the art to which this invention relates and areintended to be within the scope of the claims which follow.

That which is claimed is:
 1. A method for placing an embolic agent intoan aneurysm comprising the steps of: providing a delivery catheterhaving a proximal section, an intermediate section, and a distal sectionwhich is formed from a relatively flexible polymeric material, thedelivery catheter having a first lumen and a second lumen, and thedelivery catheter having a pre-shaped retaining wire extending throughthe first lumen to form a normally deflected distal section; inserting astraightening wire into the second lumen of the delivery catheter tocause the normally deflected distal section of the delivery catheter tobecome relatively straight; introducing the delivery catheter into avessel of a patient to a position where the normally deflected distalsection is generally aligned with an aneurysm; withdrawing thestraightening wire from the second lumen of the delivery catheter tocause the normally deflected distal section to again become deflectedand thereby move to a position proximate to the aneurysm; introducing anembolic agent deployment system into the second lumen of the deliverycatheter and through the normally deflected distal section; deliveringan embolic agent into the aneurysm with the embolic agent deploymentsystem; withdrawing the embolic agent deployment system from thedelivery catheter; again inserting the straightening wire into thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to become relatively straight; and, thereafterwithdrawing the delivery catheter from the vessel of the patient.
 2. Amethod as defined in claim 1, wherein the embolic agent deploymentsystem is an embolic coil deployment system and the embolic agent is anembolic coil.
 3. A method for placing an embolic agent into an aneurysmcomprising the steps of: providing a delivery catheter having a proximalsection, an intermediate section, and a distal section which is formedfrom a relatively flexible polymeric material, the delivery catheterhaving a first lumen and a second lumen, and the delivery catheterhaving a shape retaining wire extending through the first lumen;providing an embolic agent deployment system having an elongated,flexible deployment catheter with a lumen extending therethrough, thedeployment catheter having a distal section being formed of a materialwith a durometer which exhibits the characteristic that when a fluidpressure is applied to the lumen the walls of the distal section of thedeployment catheter expand radially, the deployment catheter having asource of pressure coupled to the proximal section for applying a fluidpressure to the lumen, and the deployment catheter having an embolicagent being disposed in fluid-tight engagement within the lumen of thedistal section; shaping the distal section of the delivery catheter toform a normally deflected distal section; inserting a straightening wireinto the second lumen of the delivery catheter to cause the normallydeflected distal section of the delivery catheter to become relativelystraight; introducing the delivery catheter into a vessel of a patientto a position where the normally deflected distal section is generallyaligned with the aneurysm; withdrawing the straightening wire from thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to again become deflected and thereby move to a positionproximate to the aneurysm; introducing the embolic agent deploymentsystem into the second lumen of the delivery catheter and through thenormally deflected distal section; applying fluid pressure to the lumenof the embolic agent deployment system thereby causing the walls of thedistal section of the embolic agent deployment system to expand andrelease the embolic agent; withdrawing the embolic agent deploymentsystem from the delivery catheter; again inserting the straighteningwire into the second lumen of the delivery catheter to cause thenormally deflected distal section to become relatively straight; and,thereafter withdrawing the delivery catheter from the vessel of thepatient.
 4. A method as defined in claim 3, wherein the embolic agentdeployment system is an embolic coil deployment system and the embolicagent is an embolic coil.
 5. A method for placing an embolic agent intoan aneurysm comprising the steps of: providing a delivery catheterhaving a proximal section, an intermediate section, and a distal sectionwhich is formed from a relatively flexible polymeric material, thedelivery catheter having a lumen, and the delivery catheter having anormally deflected distal section which is pre-shaped; inserting astraightening wire into the lumen of the delivery catheter to cause thenormally deflected distal section of the delivery catheter to becomerelatively straight; introducing the delivery catheter into a vessel ofa patient to a position where the normally deflected distal section isgenerally aligned with the aneurysm; withdrawing the straightening wirefrom the lumen of the delivery catheter to cause the normally deflecteddistal section to again become deflected and thereby move to a positionproximate to the aneurysm; introducing an embolic agent deploymentsystem into the lumen of the delivery catheter and through the normallydeflected distal section; delivering the embolic agent into the aneurysmwith the embolic agent deployment system; withdrawing the embolic agentdeployment system from the delivery catheter; again inserting thestraightening wire into the lumen of the delivery catheter to cause thenormally deflected distal section to become relatively straight; and,thereafter withdrawing the delivery catheter from the vessel of thepatient.
 6. A method as defined in claim 5, wherein the embolic agentdeployment system is an embolic coil deployment system and the embolicagent is an embolic coil.
 7. A method for placing an embolic agent intoan aneurysm comprising the steps of: providing a delivery catheterhaving a proximal section, an intermediate section, and a distal sectionwhich is formed from a relatively flexible polymeric material and thedelivery catheter having a lumen; shaping the distal section of thedelivery catheter to form a normally deflected distal section; insertinga straightening wire into the lumen of the delivery catheter to causethe normally deflected distal section of the delivery catheter to becomerelatively straight; introducing the delivery catheter into a vessel ofa patient to a position where the normally deflected distal section isgenerally aligned with the aneurysm; withdrawing the straightening wirefrom the lumen of the delivery catheter to cause the normally deflecteddistal section to again become deflected and thereby move to a positionproximate to the aneurysm; introducing an embolic agent deploymentsystem into the lumen of the delivery catheter and through the normallydeflected distal section; delivering the embolic agent into the aneurysmwith the embolic agent deployment system; withdrawing the embolic agentdeployment system from the delivery catheter; again inserting thestraightening wire into the lumen of the delivery catheter to cause thenormally deflected distal section to become relatively straight; and,thereafter withdrawing the delivery catheter from the vessel of thepatient.
 8. A method as defined in claim 7, wherein the embolic agentdeployment system is an embolic coil deployment system and the embolicagent is an embolic coil.
 9. A method for placing an embolic agent intoan aneurysm comprising the steps of: providing a delivery catheterhaving a proximal section, an intermediate section, and a distal sectionwhich is formed from a relatively flexible polymeric material and thedelivery catheter having a first lumen and a second lumen; inserting astraightening wire into the second lumen of the delivery catheter;inserting a pre-shaped retaining wire into the first lumen of thedelivery catheter to form a normally deflected distal section;introducing the delivery catheter into a vessel of a patient to aposition where the normally deflected distal section is generallyaligned with the aneurysm; withdrawing the straightening wire from thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to again become deflected and thereby move to a positionproximate to the aneurysm; introducing an embolic agent deploymentsystem into the second lumen of the delivery catheter and through thenormally deflected distal section; delivering the embolic agent into theaneurysm with the embolic agent deployment system; withdrawing theembolic agent deployment system from the delivery catheter; againinserting the straightening wire into the second lumen of the deliverycatheter to cause the normally deflected distal section to becomerelatively straight; and, thereafter withdrawing the delivery catheterfrom the vessel of the patient.
 10. A method as defined in claim 9,wherein the embolic agent deployment system is an embolic coildeployment system and the embolic agent is an embolic coil.
 11. A methodfor placing an embolic agent into an aneurysm comprising the steps of:providing a delivery catheter having a proximal section, an intermediatesection, and a distal section which is formed from a relatively flexiblepolymeric material and the delivery catheter having a first lumen and asecond lumen; inserting a shape retaining wire into the first lumen ofthe delivery catheter; shaping the distal section of the deliverycatheter to form a normally deflected distal section; inserting astraightening wire into the second lumen of the delivery catheter tocause the normally deflected distal section of the delivery catheter tobecome relatively straight; introducing the delivery catheter into avessel of a patient to a position where the normally deflected distalsection is generally aligned with the aneurysm; withdrawing thestraightening wire from the second lumen of the delivery catheter tocause the normally deflected distal section to again become deflectedand thereby move to a position proximate to the aneurysm; introducing anembolic agent deployment system into the second lumen of the deliverycatheter and through the normally deflected distal section; deliveringthe embolic agent into the aneurysm with the embolic agent deploymentsystem; withdrawing the embolic agent deployment system from thedelivery catheter; again inserting the straightening wire into thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to become relatively straight; and, thereafterwithdrawing the delivery catheter from the vessel of the patient.
 12. Amethod as defined in claim 11, wherein the embolic agent deploymentsystem is an embolic coil deployment system and the embolic agent is anembolic coil.
 13. A method for placing a medical agent into a vesselcomprising the steps of: providing a delivery catheter having a proximalsection, an intermediate section, and a distal section which is formedfrom a relatively flexible polymeric material, the delivery catheterhaving a first lumen and a second lumen, and the delivery catheterhaving a pre-shaped retaining wire extending through the first lumen toform a normally deflected distal section; inserting a straightening wireinto the second lumen of the delivery catheter to cause the normallydeflected distal section of the delivery catheter to become relativelystraight; introducing the delivery catheter into the vessel of a patientto a position where the normally deflected distal section is generallyaligned with a pre-selected position within the vessel; withdrawing thestraightening wire from the second lumen of the delivery catheter tocause the normally deflected distal section to again become deflectedand thereby move to the pre-selected position within the vessel;introducing a medical agent deployment system into the second lumen ofthe delivery catheter and through the normally deflected distal section;delivering the medical agent into the vessel with the medical agentdeployment system; withdrawing the medical agent deployment system fromthe delivery catheter; again inserting the straightening wire into thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to become relatively straight; and, thereafterwithdrawing the delivery catheter from the vessel of the patient.
 14. Amethod for placing a medical agent into a vessel comprising the stepsof: providing a delivery catheter having a proximal section, anintermediate section, and a distal section which is formed from arelatively flexible polymeric material, the delivery catheter having alumen, and the delivery catheter having a normally deflected distalsection which is pre-shaped; inserting a straightening wire into thelumen of the delivery catheter to cause the normally deflected distalsection of the delivery catheter to become relatively straight;introducing the delivery catheter into the vessel of a patient to aposition where the normally deflected distal section is generallyaligned with a pre-selected position within the vessel; withdrawing thestraightening wire from the lumen of the delivery catheter to cause thenormally deflected distal section to again become deflected and therebymove to the pre-selected position within the vessel; introducing amedical agent deployment system into the lumen of the delivery catheterand through the normally deflected distal section; delivering themedical agent into the vessel with the medical agent deployment system;withdrawing the medical agent deployment system from the deliverycatheter; again inserting the straightening wire into the lumen of thedelivery catheter to cause the normally deflected distal section tobecome relatively straight; and, thereafter withdrawing the deliverycatheter from the vessel of the patient.
 15. A method for placing amedical agent into a vessel comprising the steps of: providing adelivery catheter having a proximal section, an intermediate section,and a distal section which is formed from a relatively flexiblepolymeric material and the delivery catheter having a first lumen and asecond lumen; inserting a straightening wire into the second lumen ofthe delivery catheter; inserting a pre-shaped retaining wire into thefirst lumen of the delivery catheter to form a normally deflected distalsection; introducing the delivery catheter into the vessel of a patientto a position where the normally deflected distal section is generallyaligned with a pre-selected position within the vessel; withdrawing thestraightening wire from the second lumen of the delivery catheter tocause the normally deflected distal section to again become deflectedand thereby move to the pre-selected position within the vessel;introducing a medical agent deployment system into the second lumen ofthe delivery catheter and through the normally deflected distal section;delivering the medical agent into the vessel with the medical agentdeployment system; withdrawing the medical agent deployment system fromthe delivery catheter; again inserting the straightening wire into thesecond lumen of the delivery catheter to cause the normally deflecteddistal section to become relatively straight; and, thereafterwithdrawing the delivery catheter from the vessel of the patient.